To comply with the Stage 2 Disinfection Byproduct Rule, the rolling quarterly average at each sample site must be below .080 mg/L (80 ug/L).
TTHM Chlorine Maintenance Special Samples
The North Texas Municipal Water District conducts chlorine maintenance throughout the water delivery system in February/March each year. Starting in 2018, the City of Plano began collecting samples to analyze disinfection byproducts during this time period. Samples are collected from the same 12 sites normally sampled plus the four pump stations. In 2019, special sampling was conducted twice during the maintenance period. The chart below shows the TTHM special sample results by location from both sample dates.